Biomedical subjects

Jinna M Shepherd

Publications and source records attributed to Jinna M Shepherd.

6 recordsLinked to original sources

PubMed2003

Depression of spinal motoneurons may underlie weakness associated with severe anemia.

A 37-year-old woman had a 2-week history of progressive weakness, muscle hypotonia, and absent or hypoactive deep tendon reflexes. Nerve conduction studies showed diminished H-reflexes and absent or decreased persistence of F-waves in all limbs. The patient was admitted to the hospital with a diagnosis of Guillain-Barré syndrome. Laboratory studies revealed severe anemia with a hemoglobin level of 4.1 g/dl and hematocrit of 15.1%. Immediate blood transfusion resulted in a hemoglobin of 13.2 g/dl and hematocrit of 40.2%, associated with rapid neurological recovery (normal stretch reflexes and muscle strength) and normalization of F-waves and H-reflexes. This case demonstrates that severe anemia may be associated with signs and symptoms that mimic Guillain-Barré syndrome, both clinically and electrophysiologically. It also suggests that a relative depression of spinal motoneuron excitability may be a possible mechanism for the weakness that is commonly observed in severe anemia.

Adult↗

PubMed2002

Asthma: a brief overview.

Asthma, a common chronic inflammatory disease of the airways characterized by reversible airway obstruction, is a substantial health problem without regard for age, gender, or ethnicity. Guidelines have been established to provide clinicians with evidence-based recommendations to assist in the diagnosis and management of asthma. This review offers a brief overview of the current understanding of the pathogenesis and definition of asthma, the diagnosis and classification of asthma, and the pharmacologic therapy of asthma in adults. Further studies are required to determine whether the development of new targeted treatments will be effective in the management of asthma.

Anti-Inflammatory Agents↗

PubMed2002

Hormone replacement therapy and coronary heart disease in women: a review of the evidence.

It is well documented that coronary heart disease (CHD) is the leading cause of death in women-especially postmenopausal women. The role of hormone replacement therapy (HRT) in prevention of CHD has been considered for many years. Early epidemiological studies suggested estrogen to have a potential cardioprotective role, noting that premenopausal women have a decreased risk of developing CHD compared with men. Later observational studies showed decrease of CHD risk in postmenopausal women on HRT. By 1996, estrogen (specifically Premarin) was one of the most dispensed medications in the United States. Major medical organizations such as the American College of Physicians and American College of Obstetricians and Gynecologists widely endorsed and encouraged HRT for CHD risk reduction, along with using HRT for other potential benefits (such as osteoporosis prevention). Unfortunately, recent clinical trials seem to raise more questions than provide definitive proof in the protective role of estrogen in CHD. A review of recent and ongoing observational studies and clinical trials may help guide physicians in their recommendation and discussion of the role of HRT in postmenopausal women. As this article was being prepared for publication, reports from both the Heart and Estrogen/Progestin Replacement Study Follow-up (HERS II) and the Women's Health Initiative (WHI) were published. Both studies concluded that HRT has no role in primary or secondary prevention of CHD in women.

Clinical Trials as Topic↗

PubMed2002

Phytoestrogens: a viable option?

Estrogen replacement therapy is one of the most commonly prescribed medicines in the United States by traditional medical professionals. Over the past decade, the market for complementary/ alternative therapies for hormone replacement has dramatically increased. Women are seeking more "natural" alternatives to treat menopausal symptoms. Well-designed randomized clinical trials are often lacking, as is the information on efficacy and safety. This article will review several popular herbal therapies for menopausal symptoms including phytoestrogens, black cohosh (Cimicifuga racemosa), dong quai (Angelica sinensis), chast tree (Vitex agnus-castus), and wild Mexican yam. Their use, mechanism of action, and adverse effects are outlined.

Angelica sinensis↗

PubMed2002

Low back pain.

Low back pain is a very common condition, with about 80% of people suffering from it at some point in their lives. It is usually self-limited, resolving in 4 to 8 weeks in more than 50% of patients, yet the recurrence rate is high, about 85%. Because of the complexity of the bony, muscular ligamentous, and neural elements of the back, a specific anatomic diagnosis often cannot be made. Evaluation should include a careful history and physical examination, paying particular attention to alarm symptoms or "red flags" mentioned in the text. Imaging procedures are usually not necessary because of the lack of specificity and the high rate of early, spontaneous remission. Exceptions to this include history of recent trauma, presence of red flags or chronic unremitting course. Many treatment modalities, including physical therapy, ultrasound, thermal therapy, and local injection have been tried, but most studies are inconclusive as to their effectiveness. Prolonged bed rest is not indicated. Nonsteroidal anti-inflammation agents, judicious use of muscle relaxers, and patient education about the cause and prognosis are justified.

Diagnosis, Differential↗

PubMed2002

Hyperaldosteronism: the internist's hypertensive disease.

Primary aldosteronism (PA) is a disorder typically characterized by resistant hypertension, hypokalemia, alkalosis and suppressed plasma renin activity, and excessive aldosterone production. A true estimate of the prevalence of the disorder is difficult to estimate because its detection is dependent on the awareness of the healthcare provider to the disorder, but it has generally been felt to be a rare occurrence. Its frequency of detection began to change when Hiramatsu suggested calculating the ratio of plasma aldosterone/plasma renin activity as a screening tool for the disorder. He found a ratio greater than 75 as a sensitive indicator for aldosterone-producing adenomas. Using the ratio, several investigators have found prevalence ranging from 3 to 9%. Two major classifications of PA exist: aldosterone-producing adrenal adenoma (APA) and zona glomerulosa hyperplasia (IHA). Distinguishing between these 2 entities is important clinically, because removal of a unilateral aldosterone-producing adenoma may result in correction of elevated blood pressure and hypokalemia. Thus, when evaluating hypertensive patients, PA should be suspected in those with moderate to severe hypertension or with hypertension refractory to standard treatment or in hypertensive patients with disease onset at an early age. The aldosterone-to-renin ratio is an easy, inexpensive, and rapid means of screening for the disorder. The ratio is the screening test of choice, but further confirmatory testing is required to clinch the diagnosis. Frequently employed confirmatory tests include urinary aldosterone excretion on a high-salt diet, aldosterone suppression after a saline infusion, and the fludrocortisone suppression test, which is considered the most sensitive confirmatory maneuver. Both high-resolution CT and MRI scans appear to have similar ability to differentiate between APA and IHA. As with essential hypertension, the goal of treatment is to prevent the long-term sequela of hypertension. The underlying pathology resulting in PA dictates the treatment strategy. The drug of choice is spironolactone. Surgical intervention should be entertained in those patients with PA in whom imaging studies suggest an adenoma.

Adenoma↗